Could you add a License file to clarify under what terms this can be reused/reworked?

Hi

Great site and resource. It's so to-the-point. So little waffle relative to other resources.

I did find on the 'across()' page that the last exercise has a typo / contradiction:-

Find the mean value for any variable containing the string “length”, by penguin species, with column names updated to the original column name appended with "_max" at the end

It's nothing more than being asked to append 'max' when finding the mean. It's no biggie, the end result is much the same, but I thought you'd like to know.